高原鼠兔不育控制对鸟类多样性影响（英文）

高原鼠兔种群数量过多被认为是青藏高原草地退化的主要原因之一。2007年4月,在青海省果洛州大武镇开展了高原鼠兔不育控制实验。为了解3种不育剂(炔雌醚、左炔诺孕酮和EP-1)对高原鼠兔和土著鸟类的影响,分别在2007年和2008年8-9月调查了高原鼠兔种群数量与鸟类多样性。结果表明,投药次年,炔雌醚能显著降低高原鼠兔各群数量,而对鸟类多样性和物种数均无显著影响;炔雌醚组白斑翅雪雀的数量显著低于对照组,棕颈雪雀的数量显著高于EP-1组。因此,炔雌醚能有效降低高原鼠兔种群数量,对土著鸟类多样性影响较小。使用炔雌醚开展不育控制是高原鼠兔种群管理的一种新途径。     

高原鼠兔挖掘活动对土壤中氮素含量的影响

本文通过测定不同类型高原鼠兔鼠丘和鼠丘下0 ～ 10 cm 土壤中总氮、铵态氮和硝态氮的含量变化,分析了高原鼠兔挖掘活动对土壤中无机氮含量的影响,并通过测定高原鼠兔鼠丘密度,计算了每只高原鼠兔对氮素循环的贡献。研究结果表明:不同类型鼠丘土壤中总氮含量无明显变化,铵态氮、硝态氮和无机氮含量处理间变化趋势为当年鼠丘>两年鼠丘> 多年鼠丘> 对照。方差分析结果表明,硝态氮含量在5 月时差异显著,当年鼠丘和两年鼠丘显著大于多年鼠丘和对照,无机氮含量在5 月和9 月表现为当年鼠丘显著高于对照。在不同月份,铵态氮含量月间变化趋势为5 ～ 8 月逐渐降低,至9 月略有增加,硝态氮和无机氮含量呈现“高- 低- 高-低- 高”的“W”变化趋势。方差分析结果显示,铵态氮、硝态氮和无机氮含量月间变化显著。不同类型鼠丘下0 ～ 10 cm 土壤中铵态氮、硝态氮和无机氮含量处理间和月份间变化趋势与鼠丘土壤中变化趋势基本一致,但硝态氮和无机氮含量在当年鼠丘中均显著高于对照,且不同月份间铵态氮、硝态氮和无机氮的含量差异显著(P
< 0.05)。每只高原鼠兔挖掘活动所形成的鼠丘土壤中的铵态氮、硝态氮和无机氮分别增加了162.6 mg/ kg、355.1 mg/kg 和497.7 mg/ kg。     

高原鼠兔繁殖期攻击行为的动态格局

为探讨高原鼠兔繁殖期攻击行为强度的变化、检验进化博弈理论有关预测,本研究于2009 年5 ～8 月采用标志重捕和中立竞技场法测定了高原鼠兔自然种群斗殴及进攻等行为的发生频率及持续时间。结果表明:5 月下旬及6 月上旬高原鼠兔雄性斗殴行为发生频率及持续时间显著高于7 月下旬和8 月中旬;而雌性差异不显著。5月下旬和6 月上旬,高原鼠兔雄性个体间的斗殴行为发生频率及持续时间显著高于雌性,其余时期两性间无显著差异。进攻发起者通常是该次殴斗的获胜者;自繁殖高峰期至末期,种群中雄性高原鼠兔鹰对策者比例逐渐下降,与进化博弈论的预测一致。     

Social and ecological influences on dispersal and philopatry in the plateau pika (Ochotona curzoniae)

Benefits and costs of dispersal and philopatry of the socialplateau pika (Ochotona curzoniae) were studied on the Tibetanplateau for 3 years. Although short-lived, plateau pikas livein cohesive family groups that occupy burrow systems in sedgemeadow habitat Most (57.8%) plateau pikas were philopatric,and dispersal movements were extremely restricted. No juvenilefemales or adult pikas moved more than two family ranges betweenyears; the greatest observed dispersal distances were by twojuvenile males that moved five family ranges from the familyof their birth. Traversing unfamiliar habitat was not a costof pika dispersal because most dispersers settled in familiesthat they could easily visit before dispersal. Dispersal movementsappeared to result in equalization of density among pika families,an expected result if competition for environmental resourcesinfluenced dispersal. Males did not disperse to gain advantagesin competition for mates, as evidenced by their moving to familieswith significantly fewer females. Females, however, moved tofamilies with significantly more males. Males provide abundantpaternal care, and significantly more offspring per female survivedto become adults from families with more adult males per adultfemale. Evidence concerning the influence of inbreeding avoidanceon natal dispersal was indirect. Some males exhibited natalphilopatry; thus some families had opportunity for dose inbreeding.Males and females that dispersed had no opposite-sex relativesin their new families. Philopatric pikas may have benefitedby remaining in families that exhibited low local densities,and philopatric females might have benefited from social cooperationwith relatives.     

种群密度对高原鼠兔类固醇激素水平的影响

本研究于2003 年在野外条件下,通过比较不同密度种群间高原鼠兔的种群增长、4 种类固醇激素水平和肾上腺重量的变化,探讨种群密度与其内分泌水平间的相互关系。结果表明,在最高密度的种群内高原鼠兔种群密度增长最大,在最低密度种群内种群密度增长最小。繁殖盛期时高密度种群内雄性高原鼠兔血浆皮质酮水平显著高于低密度种群内个体,肾上腺重量在不同密度种群间也有显著差异,而血浆雌二醇、睾酮、皮质醇水平均未表现出种群密度间的显著变化。整个繁殖期内,高密度和低密度种群间高原鼠兔的皮质酮水平和肾上腺重量呈现不一致的季节变化模式,高密度种群内繁殖盛期和中期显著高于其它繁殖时期,低密度种群内则无明显变化。不同密度种群内高原鼠兔的雌二醇、睾酮、皮质醇水平的季节性变化具有相似的模式。本研究结果表明,在当前种群密度相对较低的自然情况下,高种群密度不能使高原鼠兔产生强烈的社群应激,从而限制其种群增长。     

高原鼠兔四个地理种群的遗传多样性与遗传分化

采用7 个多态微卫星DNA 标记分析了4 个高原鼠兔地理种群(海晏种群、西大滩东种群、西大滩西种群和昆仑山种群)的遗传多样性和遗传分化。采用多态信息含量(PIC)、期望杂合度(H_e )、观测杂合度(H_o)、基因流(N_m )和基因分化系数(F_st )对种群及物种的遗传多样性水平进行分析;计算各种群间的遗传距离(GD)、遗传相似度(GI)以及遗传距离与地理距离的相关系数,并进行UPGMA 聚类分析。研究结果显示,高原鼠兔的遗传多样性在小哺乳动物中处于较高水平, 其H_e 和H_o 的平均值分别为0. 5332 和0. 6003, 其F_st 为0. 0975,即有9. 75% 的变异存在于种群之间,即变异主要存在于种群内部。4 个种群间的杂合度与多态信息含量均无显著差异,说明它们的遗传多样性水平基本相当。海晏种群与其余3 个种群的遗传分化均达到了中度分化水平(F_st = 0.1043),而另3 个种群间几乎没有分化(F_st = 0. 0253)。Mantel test 结果表明地理距离与遗传距离间没有显著的相关性。     

一种醇类雄性不育剂对高原鼠兔精子的影响

高原鼠兔(Ochotona curzoniae),隶属于兔形目(Lagomorpha),鼠兔科(Ochotonidae),又名黑唇鼠兔,主要分布于青藏高原及其边缘地带,栖息于海拔4 000 m左右的宽谷草原草甸区(王酉之和胡锦矗,1999),在食物链中扮演着重要的角色,是青藏高原草原生态系统中的关键物种.近年来随着全球变暖、若尔盖湿地水位下降等因素,高原鼠兔在若尔盖湿地繁殖加快,高原鼠兔成了危害草原生态系统的主要害兽(刘少英,2005).1997年,若尔盖湿地高原鼠兔平均种群密度为6 400只/km2(刘少英和冉江洪,1999),据我们2007年的调查显示,平均种群数量上升到25 000只/km2,控制鼠兔数量迫在眉睫.     

食物及洞道密度对高原鼠兔冬季死亡率的影响

本研究在野外围栏条件下采用2×2 析因实验设计,通过最小存活数法分别统计冬季前后种群数量,测定附加食物及洞道密度对高原鼠兔冬季死亡率的影响,旨在检验栖息地质量对降低高原鼠兔冬季死亡率的效应。4种野外实验处理2 个重复的研究结果表明,夏季无附加食物与低密度洞道处理组高原鼠兔冬季死亡率为71% ;而附加食物和高密度洞道处理冬季死亡率仅为47% ;添加食物和低密度洞道及无附加食物和高密度洞道处理组种群死亡率分别为60% 和53% 。每一处理组雌性死亡率均显著低于雄性。夏季添加食物和增加洞道密度均能明显地降低高原鼠兔种群冬季死亡率,但无显著的交互作用。     

高原鼠兔对高寒草甸植物群落生物量的影响

2010 年和2011 年8 月在青海省果洛州矮嵩草草甸,采用样方法测定了不同密度高原鼠兔栖息地内杂草斑和秃斑植物群落特征及地上生物量的变化。结果表明:2010 年与2011 年相比,相同高原鼠兔密度的栖息地内杂草斑和秃斑植物总盖度、平均高度和总地上生物量差异不显著,但同一年份不同密度栖息地间差异显著。高原鼠兔低、中、高密度栖息地植物总盖度、平均高度和总地上生物量显著低于无鼠兔对照组(P < 0.05),不同密度间无明显变化规律。低、中、高密度栖息地的莎草、禾草和豆科植物盖度、平均高度和地上生物量显著低于无鼠兔对照组(P <0.05),秃斑上豆科植物消失;杂类草平均高度在低密度栖息地和无鼠兔对照组显著高于中、高密度栖息地(P < 0. 05),盖度和地上生物量对照组最小,随高原鼠兔密度增加呈增加趋势。2010 年和2011 年,高原鼠兔低、中、高密度栖息地内杂草斑面积分别占样地面积的4. 0% 、4.3% 、13. 3% 和3.8% 、4. 3% 、11. 0% ,秃斑面积分别占样地面积的0 2% 、2 6% 、4 0% 和0 2% 、2 2% 、3 4% ;植物损失地上生物量分别为110.84 kg/ hm² 、203. 18 kg/ hm² 、431.58 kg / hm² 和107.67 kg / hm² 、189. 46 kg / hm² 、365. 72 kg/ hm² 。高原鼠兔
的密度(x)与植物损失地上生物量(y)之间存在对数曲线关系,说明高原鼠兔的活动显著降低了植物总盖度、平均高度和总地上生物量,同时也改变了植物功能群组成。随高原鼠兔密度增加,栖息地内杂草斑、秃斑的面积和植物损失地上生物量呈增加趋势。     

单宁酸对高原鼠兔和根田鼠生殖激素的影响

高原鼠兔和根田鼠是生存于青藏高原的小哺乳动物,它们所取食的高原植物含有多种次生化合物。为了证明食物中的次生化合物对高原鼠兔和根田鼠繁殖相关激素的影响,探讨它们与取食植物间的协同进化,分别对两种动物灌服0、5、10 和20 mg/ kg BW 剂量单宁酸1 d、3 d 及5 d 后,测定其下丘脑促性腺激素释放激素、血浆中睾酮和血浆雌二醇的含量。结果表明,单宁酸对高原鼠兔的LD₅₀ 为112 ±27.72 mg/ kg BW,对根田鼠的LD₅₀ 为117 ± 17.37 mg/ kg BW;单宁酸可以使高原鼠兔和根田鼠血浆睾酮和雌二醇水平升高,但对下丘脑促性腺激素释放激素水平没有明显的影响。说明单宁酸可能会促进这两种动物的性成熟,有利于它们的繁殖。     

Effects of temperature and photoperiod on thermogenesis in plateau pikas (Ochotona curzoniae) and root voles (Microtus oeconomus)

We examined the effects of temperature and photoperiod on metabolic thermogenesis and the thermogenic characteristics of brown adipose tissue in plateau pikas (Ochotona curzoniae) and root voles (Microtus oeconomus), the dominant species of small mammals in the alpine meadow ecosystems on the Qinghai-Tibetan Plateau. Pikas and voles were acclimated in the following groups: (1) Long day – warm temperature (16L:8D, 23 °C), (2) Long day – cold temperature (16L:8D, 5 °C), (3) short day – warm temperature (8L:16D, 23 °C), and (4) short day – cold temperature (8L:16D, 5 °C). Both temperature and photoperiod were important environmental cues for changes in thermogenesis for both species. Low temperature and short photoperiod induced increases in metabolic rate, nonshivering thermogenesis (NST), mitochondrial protein contents of brown adipose tissue, and cytochrome C oxidase activity of brown adipose tissue mitochondria in both species. Plateau pikas were more sensitive to cold (79% of the total NST response) than to short photoperiod (21%), while root voles were more sensitive to short photoperiod (60% of the total NST response) than to cold (40%), although cold clearly enhanced thermogenesis. Their thermogenic characteristics correlated with their preferred habitats: plateau pikas are found mainly in more exposed microhabitats in open sunny meadow, while root voles live in more sheltered microhabitats in relatively closed shrub. Our results also showed that temperature and photoperiod combined induce thermogenic adjustments in both species in seasonal acclimatization in their alpine meadow macrohabitat. Accepted: 10 November 1998     

高原鼠兔脑红蛋白基因的克隆与组织表达

克隆高原鼠兔脑红蛋白(Neuroglobin,NGB)基因编码区并检测其在成年高原鼠兔脑组织和其他组织中的表达,同时探讨高原鼠兔低氧适应的分子生物学机制。从高原鼠兔脑组织中提取总RNA,通过RT - PCR 获得高原鼠兔NGB cDNA,将其与pGEM - T Easy 载体连接,构建重组质粒,蓝白斑筛选阳性克隆并进行鉴定和测序;制备地高辛标记的RNA 探针并采用原位杂交法(In suit hybridization,ISH) 分析脑红蛋白基因在高原鼠兔脑组织中的分布;采用RT - PCR 和蛋白印记(Western blot)检测高原鼠兔不同组织中脑红蛋白的表达含量。将含有目的片段的阳性克隆经测序和Blast 分析,显示其部分编码序列与GenBank 中绵羊、大鼠等同源性很高(大于84% ),表明本实验所克隆的序列为脑红蛋白基因;原位杂交结果显示NGB 在青藏高原土著动物高原鼠兔脑部分布较为广泛;高原鼠兔不同组织中都有NGB mRNA 表达,NGB 基因并不是中枢神经系统所特有的,睾丸和肾上腺也有较高的表达。NGB 基因在高原鼠兔脑组织和其他组织中分布较为广泛,推测NGB mRNA 可能在高原鼠兔机体较为广泛的区域中发挥着作用,同时为高原低氧适应相关基因的研究提供了实验依据。     

Leptin cDNA cloning and its mRNA expression in plateau pikas (Ochotona curzoniae) from different altitudes on Qinghai-Tibet Plateau

Leptin, an adipocyte-derived hormone, plays an important role in body energy homeostasis. Plateau pika (Ochotona curzoniae), an endemic and keystone species living only at 3000-5000 m above sea level on Qinghai-Tibet Plateau, is a typically high hypoxia and low temperature tolerant mammal with high resting metabolic rate (RMR), non-shivering thermogenesis (NST), and high ratio of oxygen utilization to cope with harsh plateau environment. To explore the molecular mechanism of ecological acclimation in plateau pika, we first cloned pika leptin cDNA and compared its mRNA expression in different altitudes (3200 and 3900 m) using real-time RT-PCR (Taqman probe) technology. The full-length pika leptin cDNA was 3015 with 504 bp open-reading frame encoding the precursor peptide of 167 amino acids including 21 residues of signal peptide. Pika leptin was 70-72% homologous to that of other species and was of similarly structural characteristics with other species. The pika-specific genetic diversity in leptin sequence occurred at twenty sites. With the increase in altitude, there were larger fat store and high level of ob gene expression in plateau pika. Our results indicated that leptin is sensitive to cold and hypoxia plateau environment and may play one of important roles in pika's ecological adaptation to harsh plateau environment.     

艾美耳混合球虫对高原鼠兔致死毒力的初步研究

球虫是专一性地寄生于宿主体内且对宿主有很强致死性的一种原生动物。艾美耳球虫是高原鼠兔的主要寄生物。利用艾美耳球虫防治高原鼠兔将具有重要的生态学意义和应用价值。本研究通过人工感染不同剂量的艾美耳混合球虫研究了对高原鼠兔的致死毒力。高原鼠兔的成体死亡率与球虫的感染剂量呈正相关关系,感染600 × 10⁴ 个/ mL 剂量的球虫可导致大部分高原鼠兔成体死亡,而感染60 ×10⁴ 个/mL 剂量的球虫可导致全部亚成体死亡;成体和亚成体的死亡率无性别间的差异,其死亡时间分别为第4 d和第8 d。感染60 × 10⁴ 个/ mL 剂量球虫的高原鼠兔随粪便排出的卵囊数量最大。本研究结果表明,艾美耳球虫对高原鼠兔的非急性致死效应类似于慢性杀鼠剂的作用。如果野外大剂量投放艾美耳球虫制剂后,不仅有望短期内有效降低高原鼠兔种群数量,而且其控制效果可具长效性的潜在优点。     

Phenotypic plasticity of reproductive traits in response to food availability and photoperiod in white-footed mice (Peromyscus leucopus)

Changes in photoperiod, ambient temperature and food availability trigger seasonal acclimatization in physiology and behavior of many animals. In the present study, seasonal adjustments in body mass and in several physiological, hormonal, and biochemical markers were examined in wild-captured plateau pikas (Ochotona curzoniae) from the Qinghai-Tibetan plateau. Our results showed that plateau pikas maintained a relatively constant body mass throughout the year and showed no seasonal changes in body fat mass and circulating levels of serum leptin. However, nonshivering thermogenesis, cytochrome c oxidase activity, and mitochondrial uncoupling protein 1 (UCP1) contents in brown adipose tissues were significantly enhanced in winter. Further, serum leptin levels were positively correlated with body mass and body fat mass while negatively correlated with UCP1 contents. Together, these data suggest that plateau pikas mainly depend on increasing thermogenic capacities, rather than decreasing body mass, to cope with cold, and leptin may play a potential role in their thermogenesis and body mass regulation.     

Genetic Variation Within and Among Populations of Rhodiola alsia (Crassulaceae) Native to the Tibetan Plateau as Detected by ISSR Markers

Genetic variation of 10 Rhodiola alsia (Crassulaceae) populations from the Qinghai–Tibet Plateau of China was investigated using intersimple sequence repeat (ISSR) markers. R. alsia is an endemic species of the Qinghai–Tibet Plateau. Of the 100 primers screened, 13 were highly polymorphic. Using these primers, 140 discernible DNA fragments were generated with 112 (80%) being polymorphic, indicating pronounced genetic variation at the species level. Also there were high levels of polymorphism at the population level with the percentage of polymorphic bands (PPB) ranging from 63.4 to 88.6%. Analysis of molecular variance (AMOVA) showed that the genetic variation was mainly found among populations (70.3%) and variance within populations was 29.7%. The main factors responsible for the high level of differentiation among populations are probably the isolation from other populations and clonal propagation of this species. Occasional sexual reproduction might occur in order to maintain high levels of variation within populations. Environmental conditions could also influence population genetic structure as they occur in severe habitats. The strong genetic differentiation among populations in our study indicates that the conservation of genetic variability in R. alsia requires maintenance of as many populations as possible.     

Plasmodium relictum (lineage SGS1) and Plasmodium ashfordi (lineage GRW2): the effects of the co-infection on experimentally infected passerine birds

The effects of avian malaria parasites of the genus Plasmodium on their hosts are insufficiently understood. This is particularly true for malarial co-infections, which predominant in many bird populations. We investigated effects of primary co-infection of Plasmodium relictum (lineage SGS1) and Plasmodium ashfordi (GRW2) on experimentally infected naive juveniles of siskin Spinus spinus, crossbill Loxia curvirostra and starling Sturnus vulgaris. All siskins and crossbills were susceptible but starlings resistant to both these infections. A general pattern of the co-infections was that heavy parasitemia (over 35% during peaks) of both parasites developed in both susceptible host species. There were no significant effects of the co-infections on mean body mass of the majority of infected birds. Mean haematocrit value decreased approximately 1.5 and 3 times in siskins and crossbills at the peak of parasitemia, respectively. Mortality was recorded among infected crossbills. We conclude that co-infections of P. relictum and P. ashfordi are highly virulent and act synergetically during primary infections in some but not all passerine birds.     

Inventory of the carabid beetle fauna of the Gaoligong Mountains,western Yunnan Province,China: species of the tribe Zabrini (Coleoptera,Carabidae)

A ten-year multidisciplinary, multi-national and multi-institutional biodiversity inventory project in the Gaoligong Shan region of western Yunnan Province, China generated more than 35,000 specimens of the beetle (Coleoptera) family Carabidae. In this report, first of a planned series, we focus on diversity in tribe Zabrini. Our study of just over 1300 specimens of zabrine carabids from the project, all in genus Amara Bonelli, found a total of 13 species, all previously described, to occur in the study area, with none of them strictly endemic. We present a key for identification of adults of these species, as well as nomenclatural data, diagnoses, illustrations of dorsal habitus and male genitalia, and information about geographical, altitudinal and habitat distributions within the study area and overall geographical distribution for each species. Distributions of the species within the study area are compared, and broader geographical range patterns are characterized. We also discuss a possible role of the Gaoligong Shan region as one source area for the present-day fauna of the Himalaya and southern edge of the Qinghai-Xizang (Tibetan) Plateau.     

Species and ecads of Caulerpa (Ulvophyceae,Chlorophyta) in Malesia (South-East Asia): Taxonomy,biogeography and biodiversity

In the present paper 29 species ofCaulerpa from Indonesia, the Philippines and Papua New Guinea are listed, with reference to their distribution and occurrence of ecological phenotypes (ecads). Other names ofCaulerpa taxa recorded for Malesia in literature are dealt with in the paragraph on excluded and changed names. The variability and nomenclature of mainly the species recorded from Indonesia are discussed, especially regarding the implications of the recognition of ecads in several species. The ecads in the sectionSedoideae are discussed as an example of use of the designation ecad for a number of growth forms. Biogeography of the genusCaulerpa is discussed with focus on areas of high biodiversity, both inside and outside Malesia, followed by a discussion on biodiversity assessment. It is suggested that the genusCaulerpa is a good indicator for the quantitative assessment of biodiversity. The need for a modern world-monograph of this genus is stressed. Such a monograph can be a stimulus for ecosystem studies ofCaulerpa stands.